Internal combustion engine



Sept. 27, 1932. w. H. ROBERTSON INTERNAL COMBUSTION ENGINE Original Filed Dec. 115, 1919 4 Sheets-Sheet Inventor Zqdt/kaw,

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ifomey Sept. 27, 1932. w. H. ROBERTSON INTERNAL COMBUSTION ENGINE Original Filed Dec. 13, 1919 4 Sheets-Sheet 5 E5. /5 m/e/z for y l lorncy r Sept. 27, l932- w. H. ROBERTSON 1,880,025

INTERNAL COMBUSTION ENGINE i Original Filed Dec. 13, 1919 4 Sheets-Sheet 4 a im nren for forllgy Pafeated sept. 27, 1932 UNITED STATES WILLIAM H. ROBERTSON, or DAYTON, omo

INTERNAL coMBUsTIoN ENGINE Y Substitute application filed December 13; 1919, Serial No. $44,715. Renewed April 5, 1929. y

This invention relates to internal combustion engines, and more especially to two cycle engines of the Diesel type.

One aim of the invention is to providevan engine having the highest possible thermal efficiency, and, in carrying out this aim, novel means are provided for securing an intimate mixture of the air for supporting combustion and the fuel separately injected into the cylinder; novel means are provided for scavenging the engine in the most effective manner; and novel means are provided for utilizing the energy of the exhaust gas.

I aim to secure high thermal eiciency by providing that the air used to support combustion shall be initially compressed by the operation of the engine and that it shall be caused to swirl through the engine cylinder 1n Y order more thoroughly to mir` with the in- 6 jected fuel. The air which enters the cylinder after the explosion has taken place is like- A wise caused to rotate as it passes through the cylinder so that, by its swirling action, this air will e'ifectivel)7 scavenge the cylinder.

In order to utilize the energy of the exhaust gas, I provide that the exhaust shall pass through a turbine, preferably of the DeLaval type, before passing into the atmosphere.

Another object of the invention is tovsecure as perfect a. dynamic balance as possible. Onemanner of accomplishing this result is to provide two oppositely' reciprocating pistons inthe cylinder, said pistons cooperating operate to oppositely revolving flywheels.

By making the moving parts of equal weight,

the vibration which one set of parts would tend to set up'ispffset by the equal and op- 1 posite effect ofthe other set of parts which operates contrariwise.

A further object is to reduce to a minimum the weight of the engine per horsepower` This object is accomplished in one manner by utilizing flywheels of comparatively small mass and gearing them up to the engine crank shafts so that theilywheel elements, by their increased speed, will be effective to produce a steady iiow of power from the engine.

In thiseonnection it is a further object a with oppositely revolving crank shafts whichI that the moving element ofthe engine oper-v ated air compressor shall act as one iiywheel ele-ment, and that the turbine rotor shall act as the other flywheelelement, thereby reducing the number of parts as well as the weight per horsepower.

Another object of the invention is to provide novel means for injectingv fuel into the engine in such a manner as to be thoroughly mixed with the combustion air toy insure a uniform fuel mixture.

A further object is t`o provide a valveless fuel pump for injecting fuel into the engine.

A further object is to provide for the control of the engine speed by controlling the operation of the pump by the engine. One manner of accomplishing this object .is to control the amount of fuel forced into the engine cylinder during each cycle of the engine operation. Y 7o A further object is 'to eliminate noise by providing a mutiier of improved construetion which will relieve theexhaust lof a large portion of its energy while permitting a rapid i escape into the outside atmosphere. In carrying out this object I provide that the exhaust turbine shall act also as the muiiier. In accomplishing this object, the number of englne parts and the weight per horsepower are reduced. 80

Other and further objects and advantages of the present invention will be apparent from the following description of a preferred embodimentthereof, reference being made to'I the accompanying drawings.

In the drawings Fig. l is a. side elevation of an engine embodying the present invention;

Fig. 2 is a sectional view taken on, line` 2-2 of Fig. 1; '90

Fig. 3, Fig. 4 and Fig. 5 are sectional views taken on line 3-3 of Fig. 2 showing the lengine parts in their relative positions during different stages of the engine cycle;

F ig. 6 is a left end elevation of the fuel iml cuf- Fig. 9, Fig. 10 and Fig. 11 are sectional views of certain parts shown in Fig. 7, showing stages of operation of the pump when set to deliver a relatively large amount of ufuel per engine cycle;

Fig. 12, Fig. 13, Fig. 14 and Fig. 15 are sectional views similar to those shown in Fig. 7, Fig. 9, Fig. 10 and Fig. 11 showing stages of pump operation when the pump is set to' deliver a relatively small quantity f fuel per engine cycle;

Fig. 16 is a. sectional view taken on line 16-16 'of Fig. 2;

Fig. 17 is a sectional view taken on line 17-17 of Fig. 2;

Fig. 18 is a. sectional view taken on line 18-18 of Fig. 1;

Fig. 19 is a sectional view taken on line 19-19 of Fig. 1;

Fig. 20 is an end elevation of the fuel nozzle; and

' 4Fig. 21 is a sectional view taken on line 21-21 of Fig. 20.

Referring to the drawings, a base 30 supports crank cases 31 and 32, which support between them a cylinder`33 in which slide pistons 34 and 35. Piston 34 is connected by rod 36 with crank 37 formed preferably integrally with crank shaft 38. Piston 35 is connected by rod 39 with crank 40 also formed integrally with crank shaft 41.

Shaft 38 directly drives gear 42, fuel-pump cam 43, and planetary gear arm 44; while turbine rotor 45 is mounted to rotate thereupon.

Shaft 41 directly drives gear 46, slide valve cams 47, 48, and planetary gear arm 49, while fan rotor is mounted to rotate thereupon.

A turbine housing 51 mounted upon crank case 31 is divided by a partition 52 into a tur\ bine gear case 53 and a turbine rotor case 54.V The end wall of housing 51 is provided with apertures 55 and with inwardly projecting ledges 56 and 57, see Fig. 16; and the cylindrical wall of housing 51 is provided with internal gear 58, which meshes with planetary gears 59 and 60, rotatably mounted on gear arm 44. Housing 51 is provided with' holes 55a see Fig. 16. Gears 59 and 60 mesh with pinion 61 attached to bearing sleeve 62 which supports turbine rotor 45. which rotates normally in the direction of arrow 45a.

Rotor 45 is provided with blades 63 arranged to be impinged upon by the exhaust gases f-which enter through exhaust pipe 64 and circulate through the rotor 45 and into rotor case 54 as indicated approximately by arrows 65. The ledge 56 divides thc spent gases into two streams which tend to; meet against'the ledxge 57 this ledge 57 serving to divert the spent gases out through holes 55. Any part of the exhaust carried around by the rotor blades may escape throughr openings 55a. f

Exhaust pipe 64 is connected with annular A fan housing is provided with a fan rotor case 81 provided with a central aperture 82 communicating with fan gear case 83,

which' in turn is connected with the interior of crank case 32 through holes 84. Housing 80 is provided with an internal gear 85, see Fig.

2 and Fig.A 17, which meshes with planetary gears 86 and 87, rotatably mounted upon gear Y arm 49. Gears 86 and 87 mesh with pinion `88 which is directly connected with fan rotor 50. The normal direction ofrotation of the gearing is indicated in Fig. 17 by arrows 49a,

86a and 88a.

Fan casing 81- is connected by air intake pipe 90 with annular intake chamber 91, see Figs. 2 and 19. chamber 91 and cylinder 33 is controlled by slideJ valve 92, provided with ports 93.

Crank case 32 supports a rod 94, see Fig. 3 which supports bell crank levers 95, 96 carrying cam rollers 97, 98 respectively, cooperating with races provided in cams 47, 48, respectively. Rollers 97 98 are connected with arms 99, 100 respectively of the valve 92.

. Levers 95, 96 ycooperate with counterbalance levers 101, 102, respectively, mounted upon rod 103 carried by crank case 32.

Crank cases 31 and 32 are provided with air inlet ports 111 and 112, respectively, closed by spring pressed valves 113 and 114, respectively, which are arranged to be opened by suction within the crank cases during the compression stroke of the pistons. Crank cases 31 and `32 are connected by pipe 115.

Referring to Figs. 6 to 8 inclusive, the fuel pump will next be described. Pulnp cam 43 is provided with races 120 and 121, cooperat-l -j ing with rollers 122 and 123, respectively, carried by levers 124 and 125, respectively. Levers 124-and 125 are connected by studs 126 and 127, respectively, with plungers 128 and 1,29, respectively, which slide wlthn sleeve 130 mounted in pump frame 131 formed preferably integrally with a side wall of crank case 31.

Frame 131 is provided with fuel inlet passage 132 connected with inlet pipe 133 which leads from a fuel tank, not shown. Passage Communication between 132 leads into inlet port 134 provided in sleeve 130. Frame 131 is provided with fuel outlet passage 135 connected with fuel outlet pipe 136 which leads to the fuel nozzle to bedescribed. Passage 135 leads out from outlet port 137 provided in sleeve 130.

Levers 124 and 125 are provided with slots 144 and 145, respectively, through which pass studsv 146 and 147, respectively, carried by ful crum plate 148. Plate 148 is provided with a slot 149 through which projects a stud v150 mounted upon a Wall of crank case 31. A spacing washer 151 is located between crank las i attached by means of stud 153a bell-crank lever 154 which is rotatably supported upon the base 30.

The cycle of operations of the pump is shown by Figs. 7, 9, 10 and 11. In Fig. 7, the plungers 128 and 129 are located in touching rela-tion opposite the fuel inletl port 134. Turning cam 43 in the direction of the arrow 155 causes the plungers first to be separated,

as shown in Fig. 9, causing fuel to be sucked into sleeve 130. Further turning of cam 43 causes plungers 128 and 129 to move equal distances to the respective positions shown in Fig. which are opposite outlet port 137. Further turning of cam 43 causes plungers 128and 129 to come together as shownin Fig. 1l, thereby causing the fuel to be forced out through pipe 136. When a revolution of cam 43 has been completed the pump plungers will be returned to the respective positions shown in Fig. 7. The pump cam 43 is timed so that fuel will begin to be ejected through pipe 136 at the end of the compression stroke.

The speed of the engine is controlled by moving lever 154 so as to raise or lower the fulcrum studs 146 and 147. lf studs 146 and 147 be moved to the upper-most position much less fuel will be pumped from the fuel tank\ and ejected into pipe 136. With the fulcrum studs in such a position, the operation will be as illustrated in Figs. 12, 13, 14 and'15 showing positions of the plungers corresponding to Figs. 7, 9, 10 and 11 respectively. It will be observed in Fig. 13 that the plungers are retracted to a lesser extent thanrin Fig. 49. Therefore, a smaller amount of fuel is sucked into the pump and ejected when the plungers come together again as shown in Fig. 15.

The fuel nozzle designated asa whole byy numeral 160 will now be described. Nozzle 160 comprises casting'161 extending through the cylinder wall and provided with a passage 162 connected with pipe 136. Passage 162 leads into passage163 arranged axially of cylinder 33; and in passage 163 is loosely journalled a shaft 164, provided at each end with a perforated disc 165. v

Gears 42 and 46 meshl with gears 170 and 171, respectively, carried by shaft 172 which is rotatabl mounted upon frame and carries a driving pulley 173. Pulley 173 may be provided with a crank 174 for starting the engine.

The operation of the engine is as follows:

Air for combustion and scavenging purposes is drawn during the suction stroke, through ports 111 and 112; into the crank cases 31 and 32. During the operation of the engine, thevfan draws air in through pas-- sages 84 and blows it out through air intake pipe 90 and into annular passage 91 where it is initially compressed. This air enters the cylinder 33 at a. time to be described later 4'and is caused to swirl by reason of the tangential relation `ofv pipe 90 to the passage 91.

This swirling motion is indicated roughly by yarrows 91a. This swirling air is moved toward nozzle 160 during the compression stroke and causes discs 165 to rotate.

At low speed valve ports 111, 112 are closed during the expansion stroke of the pistons and whatever air enters the cylinder after the expansion stroke is nearly finished and the cylinder intake opens, is due mainly to the pump actions of the pistons.

At high speed, however, thesevalves are constantly'open because the fan blowel.` attains suiiient speed to compress the air before it enters the cylinder. Therefore, at this high speed the blower furnishes a greater volume of air t6 the cylinder than that furnished, Vmerely by the displacement of the pistons. .Hence, the partial vacuum which it creates due to sucking air through the crank cases faster than the pistons could pump it, would lcreate a sufficient vacuum to keep the valve ports 111, 112 open Constantly.

At the end of the compression stroke fuel is ejected through nozzle 160 and spreads out over the` surfaces of the discs 165 and fills the perforations. The swirling air as it passes through the perforated discs picks up the fuel drops and causes them to be whirled around together with the fuel mist which is thrown oif the edges of the rotating discs. In this manner an intimate mixture of fuel and combustion air is rapidly secured.

The fuel is preferably ignited Yby the heat of compression, although the well., .known forms of electrical ignition may be 'used at the start. The combustion 'space is preferably 'one-twelfth the displacement .space so that the air will be raised to a temperature suiiicient for fuel ignition purposes by compressing it within the cylinder.

During 'a 'portion of the combustion stroke the fuel continues toi burn, and to develop power for driving the pistons. The fuel pump is operated so that the maximum amount of fuel injected is sufficient to consume substantially all of the'combustion air when the engine operates at full load. The

wardly, from positions shown in Fig.2 to

positions shown in Fig. 3, this movement being indicated by arrows 34a and 35a, the exhaust ports 71 will be uncovered before the piston 35 uncovers ports 93. The swirling "'90 where nearest piston 35.

n that the pisto be given up to the rotor to assist in driving vthe engine. The passing of the exhaust *im through the rotor and the dividing .of it by ledge 56 into two streams. which, meet against the ledge 57 is effective in preventing the sudden rush of the exhaust into the atmosphere.

By the time piston 34 has moved to outer in dead-center position (see Fig. 4), piston 35 "will have completely uncovered ports 93 in valve 9", permitting the initially compressed air in the chamber 91 to rush in and blow out the dead air at the endof the cylinder As therotation of shafts 38 and 41 continues in the direction o`f arrows 38a and 41a,

. `respectively, the pistons 34 and 35 move in direction of arrows 341) and 35b, respectively. u While exhaust ports 71 are being coyered by the piston 34, valve 92 is being moved to open position by cams 47 and 48, so that by the time ports 71 are fully covered, valve 92'is in full open position as shown in Fig. 5. Before ports 71 are closed, fresh air, which has been initially compressed by the outward movement of the plstons or thecentrifugal blower depending upon the sp'eed of the motor, will swirl through the cylinder and .com letely drive out the exhaust. This vfres air by its whirling motion tends to maintain its'own plane of rotation, and, therefore, the mixing -of the fresh air with the dead air will be reduced to a minimum.

M After ports 71 are closed, the slide valve 92 remains open, permitting additional fresh air to pile up whatevery pressure the blower msylgenerate.

an ordinary two-cycle'engine the in "45 take port would havebeen opened sooner than an ordinary two-cycle engine, the intake port would'also have been closed before the ex' `haust rt closed, -thereby allowing less time for fresh air to enter to drive out the exhaust, than isl the case of the present invention. Therefore the present inventionis adapted to be operated at a much higher speed than the ordinary two-cyclev engine.

A further advantage of the present invention over the ordinary two-cycle engine 1s ns displace a volume of air in the crank cases equal to a very large percent of -the total crank case and .cylinder volume. The result is that the pistons themselves raise the ressureof the air higherthan in the case of vtllie ordinary twofcycle engine where the ratio of piston displacementto volume is relatively small.-

-After piston 35 closes off communication between passage 91 and cylinder 33, valve 92 begins moving to closed position which it 7. reaches by the time piston 35 has'reached inner dead-center position.

When the pistons 34 and 35 have reached the inner dead-center positions shown in Fig. 2, fuel is again injected and burned, and the cy'cle of operations which has been described is repeated. v

During the burning of the fuel the mixing of the burnt air with fresh air is reduced to a minimum in the present invention. TheI fresh air is caused to whirl as it enters the cylinder by means hereinbefore described. As this air is compressed it is still whirling and the fuel nozzle discs 165 take up this motion. By the) time the pistons reach the. inner dead-center 'the air is still whirlin crank case A though retarded by the fuel nozzle stem an by friction of cthe air itself. However, the discs 165 have stored some energy durin the first part of thecompression stroke and give up this energy to the air during the latterpartof the" compression stroke tend'- ing to maintain vthe whirling motion. With the pistons located at inner dead-center, mostl of the compressed air is confined between the vdiscs 165. As'the pistons 34 and 35 separate, the air expands through and around the discs carrying thefllel oil with it, which burnsv as it is ejected lfrom the nozzle'and mixes with the air. The air supporting combustion has still enough whirling motion4 to maintain itself in its own plane of rotation and, therefore, the burnt airy does not ten to mix with the fresh air which is pushing-f outwardly from the center point of the cylinder toward the outer ends thereof.

Vibration is substantially eliminated by providing in the one cylinder, two pistons', f of equal weight which drive two crank shafts in oppositev directions through connecting rods and cranks of equal weight; and b providing thatthe two shafts together wit the respective parts rotating therewith shall develop equal kinetic energies. Since there is only one slide valve, the oscillating counterbalances lOl-and 102 are provided.

By eliminating vibration, the extent of use of the engine is greatly'increased. It can be operated without a heavy foundation and therefore may be readily transported while in operation. It can, therefore, be construeted as a portable power device for ,all= sorts of purposes, including domestic use and use as the prime mover of a portable l hand tool such as a drill, saw or planer.

The portability of the engine is further increased bythe use of small il wheels which are' eared up to the. crank shafts so as to deve op the same energy of rotatiop as the l conventional large iiywheel directly connected to the crank shaft.

The gearing up of the flywheels is taken advantage of by constructing the iiywheels so that one may act as a high-speed fanv rotor, and the other may serve as a turbine rotor converting some of the energy of the exhaust into useful power, and, at the same time, serving as one element of an exhaust muiiier.

It is to be understood that the invention is not` restricted to the particular impulse turbine disclosedbut that other typessuch as the conventional DeLaval type may be used. In lsuch a case the exhaust would enter on one side of the-turbine rotor and leave on the opposite side, and would then pass into muiiier passages in the turbine case and then out intothe atmosphere.

It is to be understood that some form of cooling system is used for cooling the cylinder and fuel nozzle. For sake of clearness, the/cooling system has been omitted from the drawings. n

While the form of mechanism herein shown and described constitutes a preferred form of embodiment of the invention, it is to be understood that other forms might be adopted, all coming within the scope ofthe claims which follow.

This specification is a substitute for my original specification Serial No. 344,715, filed December 13, 1919.

What I claim is as follows:

1. Inan internal combustion engine, the

.-f combination with a cylinder and a piston re- :iprocating therein, said cylinder having inlet and outlet port-s; of means for initially compressing the combustion air; means for causing the air to take up a whirling motion as it enters the cylinder; means for maintaining a rotation of the air; means for injecting fuel; and means permitting the exhaust to leave the cylinder by a similar whirling motion. A

2. In an internal combustion engine, the combination with a cylinder and a piston reciprocating therein, said cylinder having an inlet port adjacent one end and an outlet port adjacent the other end; of means for initially compressing the combustion air; means for causing the air to take up a whirling motion as it enters the cylinder; means for maintaining a rotation of the air; means for injecting fuel; and means permitting the exhaust to eave the cylinderl by a similar whirling motion.

3. In an internal combustion engine,`the combination with a cylinder and a piston reciprocating therein, said cylinder having inlet and outlet ports; of means for initially compressing the combustion air; means for causing the air to take up a whirling motion as 1t enters the cylinder; means for 'injecting fuel; and means for maintaining a rop tation of the alr and for spraying the fuel.

4. In an-internal combustion engine, the

combination witha cylinder and a piston reciprocating therein, said cylinder having an inlet port 'adjacent one end and an outlet portl adjacent the other end; of means for initially compressing the combustion air means for causing the air to take up a whirling motion as it enters the cylinder; means for injecting fuel; and means for maintaining a rotation of the air and for spraying thev fuel.

5. In an internal combustion engine, the

combination with azcylinder and a piston reejciprocating therein, said cylinder having inlet and outlet ports; of means .for initially compressing the combustion air; means vlfor causing the air to take up a whirling motion as it enters the cylinder; means for injecting fuel; and rotating means fontaking up the whirling motion of the incomlng air, and laterfor imparting motion to the air.

6. In an internal combustion engine, the combination with a cylinder and a piston reciprocatingr therein, said cylinder having an inlet port ,adjacent one end and an outlet port adjacent the other end; of means -for initially compressing the combustion air; means for'reusing the air to take up a whirling motion as it enters' the cylinder; means for injecting fuel; and rotating means for taking up the whirling motion of the incoming air, and later,'for impart-4 ing motion to the air.

7. In an internal combustion engine, the combination with agcylinder and a pair of pistons reciprocating oppositely therein, said cylinder having air inletand exhaust ports; of means for initially compressing the combustion air; means for causing the air to take up a whirling motion as it enters the cylinder; means for injecting fuel; 'and means located in the clearance space between' means for injecting fuel; and means located in the clearance space between the pistons for maintaining a rotation of the air.

9. In an internal combustion engine, the combination with a cylinder and a pair of pistons reciprocating oppositely therein, said cylinder having an air inlet port locatedadjacent one end, and an exhaust port located adjacent the other end thereof; of means for initially compressing the combustion air.; means for causing the air to take up a whirling motion asit enters the cylinder; means for l fi injecting fuel; and rotatable means located in the clearance space between the pistons for i taking up the whirling motion of the incom-y ing a1r, and later, for imparting motion to 5 the air.

l0. In an internal combustion engine, the combination with a cylinder and a pair of pistons reciprocating oppositely therein, said cylinder having an air inlet port located adi jacent one end and an exhaust port located adjacent the other end thereof; of means for `initially compressing the combustion air; meansfor causing the air to take up a whirling motion as it enters the cylinder; means l5 for injecting fuel; and rotatable means located in the clearance space between the pistons for taking up the whirling motion ofthe t incoming air, and later, for imparting motion to said air, said rotatable means operating to mix the fuel'and whirling air.

11. In an internal combustion engine, the combination with a cylinder and a pair of pist'ons reciprocating oppositely therein, said cylinder having an air inlet port located adjacent one end and an exhaust port located adjacentthe other end thereof; of means for initially compressing the combustion air; means for causing the air to take up a whirling motion as it enters the cylinder; means for injecting fuel; and rotating discs sup'- ported by the cylinder between the pistons for taking up the whirling motion of the incoming air, and later, for imparting motion Q to said air, said rotating discs operating to mix the fuel and whirling air.

12. In an internal combustion engine,`the combination with a cylinder'and a pair of pistons reciprocating oppositely therein, said cylinder having an air inlet port located ad- 49 jacent one end and an exhaust port located adjacent the other end thereof; of means for Vinitially compressing the combustion air;`

means for causing the air to take up a whirling motion as it enters the cylinder; meansV '45 for injectingx fuel' and rotatingdiscs mount- J ed upon a aft, loosely journalled within a member supported by the cylinder, said member having a fuel passage leadingto saidV shaft and connected with the fuel injecting 5 means. i

13. In an internal combustion engine, the combination with a cylinder and a air of pistons reciprocating oppositely therein, said .cylinder having an air inlet port located adjacent one end and an exhaust port located adjacent the other end thereof; of means for initially compressing the combustion air; means for causing the air to` take up a whirling 'motion as 1t enters the cylinder; means for 0 injecting fuel; and rforated rotating dises mounted upon a s aft, loosely journalled .within a member supported by the cylinder,

said member having a fuel passage leading to said shaft and connected with the fuel in- 05 jecting means.` i.

-adjacent the other end thereof, one of said intake port controlled by the other piston.

jacent one end and an exhaust port located IQ adjacent the other end thereof; of means'bfor initiall compressing the combustion air; means or causing the air to take up a whirling motion asit enters the cylinder; means for injecting fuel; and perforated rotating discs mounted at each Iend of a shaft loosely journalled within a member supported by the cylinder, said member having a fuel passage leading to said shaft and connected with the fuel injecting means. J

15. In an internal combustion engine, the combination of a cylinder and a pair of pistons reciprocating oppositely therein, said cylinder having an air inlet port located" adjacent one end, and an exhaust port locatedl 95 adjacent the other end thereof, one of said pistons controlling the opening of the exhaust port; and an engine operated sleeve valve in which the other piston slides for controlling the opening of the air intake port.

16. In an internal combustion engine, the combination of a cylinder and a pair of pis- 'tons' reciprocating oppositely therein, said cylinder having an air inlet portjlocated adjacent one end, and an exhaust port located adjacent the other end thereof, one of said pistons controlling the opening-of the exaust port; and an engine operated sleeve valve in which the other piston slides for controllin the opening of the air intake port; said s eeve valve having auxiliary intake j.

ports controlled by the 'movements of said sleeve valve and said other piston.

17. In an internal combustion engine, the combination of a cylinder and a pair of pistons reciproca-ting oppositely therein, said cylindei` having an air inlet port located ad'acent one end, and an exhaust port located adjacent the other end thereof, one of said pistons controlling the opening of the ex.-

aust port; and an engine 'operated sleevevalve in which the other piston slides for controlling the openin of the air intake port; Y said sleeve valve having auxiliary intake ports, the'opening of-wh1ch is controlled by the movement of said other piston, and the closing of which` is controlled by the movements of both the sleeve valve and'said other piston.

18. In' an internal combustion engine, the combination of a cylinder and a pair of pistons reciprocating oppositely therein, said cylinder having a main air inlet port located adjacent one end, and an exhaust port located pistons controlling the opening of lthe exhaust port; and engine operated means for controllingA the opening of the main air intake port, said means havingan auxiliary air I9. In an inte/mal combustion engine, the' combination of a cylinder and a pair of pistons reciprocating oppositely therein, said 'cylinder having a main air inlet port located adjacent one end, andv an exhaust port located adjacent the other end thereof, one of said pistons controlling' the opening of the Y combination of a cylinder and a pair of pistons reciprocating oppositelytherein, said cylinder having a main air inlet port located l adjacent one end, and an exhaust port located adjacent the other end thereof; and engine operated sleeve valve for controlling the gotopening ofthe main air intake port, said valve havingan auxiliary air intake port; and mechanical connections between the pistons and sleeve valve whereby the exhaust port is first opened, then'the auxiliary air port' is opened while the exhaust is still opened, then the auxiliary air valve closes before the exhaust port is closed, thenvwhile the exhaust port is being closed thepmain air J port is being opened, and then the main air port is closed after the exhaustport has been closed. Y

21. In an internal combustion engine, the combination of a cylinder and a pair of pistons reciprocating oppositely therein, said cylinder having a main airpinlet port located adjacent one end, and an exhaust port located adjacent the other end't-hereof; an engine operated sleeve valve for controlling the opening of the main air intake port, said valve having any auxiliary air intake port; and mechanical connections between the pistons and sleeve valve whereby first the exhaust port is opened while the pistons advance toward outer dead center, whereby the auxiliary port is next opened, but before the pistons reach outer dead center, wherebyvthe-exhaust and auxiliary port are fully opened at outer dead center, whereby, upon the movement of the Vpistons-toward inner dead center, the auxiliary port is closed first while the exhaust .port is being closed and the main air port is being opened, and whereby the main air port is closed after the exhaust port is closed.

22L In an internal combustion engine, the

combination of a'cylinder and a pair of pistons reciprocating oppositely therein, said cylinder having a main air inlet port located adjacent one end, and an exhaust port located adjacent the other end thereof; and engine operated sleeve valve for controlling the opening of the main air intake port, said valve having an auxiliary air intake port; and mechanical connections between the pistons and sleeve valve whereby the exhaust port opens' before the auxiliary air port opens and closes after the auxiliary air port closes, but closes before the main airport closes.

23. In an internal combustion engine, the

combination of a cylinder and a pair of pistons reciprocating oppositely therein, said cylinder having a main air inlet port located adjacent one end, and an 'exhaust port located adjacent the other end thereof; and engine operated sleeve valve for controlling the open- Aing `of the main air intake port, said valve having an auxiliary air intake port; and mechanical connections between the pistons and sleeve valve whereby the exhaust port opens before the auxiliary air port opens and closes after the auxiliary air port closes, whereby the main air port begins to open as the auxiliary air port is being closed, and begins to close after the exhaust port is closed.-

24. In an internal combustion engine, the. combination of a cylinder and a pair of piston's reciprocating oppositely therein,said cylinder having an air inlet port located adjacent one end, and an exhaust port located adjacent the other end thereof; and mechanical connections between the pistonswhereby the exhaust port is first opened' but closes after the air port begins to open, and whereby the air port begins to close after the exhaust port is .fully closed.

25.l In an internal combustion engine, the combination of a cylinder and a pair of pistons reciprocating oppositely therein, said cylinder having an air inlet port located adj acent one end, and an exhaustport located adjacent the other end thereof; and mechanical connections between the pistons whereby the exhaust port is first opened, whereby just after the exhaust port is fully opened the air port begins to open but` does not begin to close until after the exhaust port is fully closed.

26. The method of burning fuel in an internal combustion engine cylinder consisting in causing the combustiony air to rotate as it passes through the cylinder, in compressing the air while maintaining the air in a state of rotation, in injecting fuel when the air is fully compressed, in causing the fuel to burn Uli' as the air expands wherebythe burnt air by ternal combustion engine cylinder 'consisting l2@ in causing the combustion air to rotate as itA passes through the cylinder, in compressing the air while maintainin the air in a state of rotation, in injecting fuel, in causing the fuel to burn as the air expands whereby the 3 burnt air by virtue of its rotatingmotion tends to maintain its plane of rotation and the tendency for the burnt air to mix with the fresh air is reduced to a minimum. i

28. In a two-cycle engine the combination of a cylinder and a piston reciprocating therein, said cylinder having inlet and exhaust ports; `and means for compressing the unburnt air in the cylinder prior to the comv pression'stroke of the piston.

. 29. In an internal combustion engine the combination of a cylinder and a piston reciprocating therein, said cylinder having inlet and exhaust ports and means whereby the unburnt air entering the cylinder is compressed therein after the exhaust port closes but before the inlet port closes and prior to the compression stroke of the piston.

30. In an internal combustion engine the combination of a cylinder and a piston reciprocating therein, said cylinder having inlet and exhaust ports and engine driven' means whereby the unburnt Yair entering the cylinder is compressed therein after the exhaust port closes but before the inlet port closes and prior to the compression stroke of the piston.

31.l In a two-cycle engine the combination of a cylinder and a pair of pistons reciprocatv' a ing oppositely therein, said cylinder having t sind exhaust ports and enginedriven means intermediate one of said pistons and cylinder and cooperating with said inlet port whereby the inlet port is opened after the exhaust port opens and is closed after the exhaust port closes.

32. In a two-cycle engine the combination K of a cylinder and a pair of pistons reciprocating oppositely therein, said cylinder havfag ing inlet and exhaust ports and means for compressing the unburnt air in the cylinder prior to the compressionstroke of the piston.

33. In a two-cycle engine the combination of a' cylinder and a piston reciprocating therein, said cylinder having inlet and exhaust ports; and centrifugal means and mechanical connections between said ports and said centrifugal means whereby the unburnt air .entering the cylinder is compressed after `the exhaust port closes but before the inlet port closes and prior to the compression stroke of the piston.

1 34. In an internal combustion engine, the v combination with a cylinder having an air 66 intake passage; of a centrifu al air compressor` connected with the intake; a piston; a shaft; mechanical connections between the piston and shaft for rotating the same; and igh speed gearing between the shaft and said .55 compressor. g

35. In an internal combustion engine, the combination with a cylinder having an air intake passage; of a centrifugal air compressor connected with the intake; means for rol thting said'centrifugal air compressor at a. relatively high speed; a piston; a shaft; and mechanical connections between the piston and shaft for rotating the same. f v In testimony whereof I affix my signature. 15 WILLIAM I-I. ROBERTSON. 

